:root {
  --bf-blue: #5b8cff;
  --bf-blue-soft: #7ca3ff;
  --bg: #f7f8fb;
  --card: #ffffff;
  --text: #1a2333;
  --muted: #6b7488;
  --mine: #e8efff;
  --theirs: #f1f3f7;
  --translated: #fff4d6;
  --border: #e3e7ef;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-text-size-adjust: 100%;
}
header {
  background: var(--bf-blue);
  color: white;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
header h1 { margin: 0; font-size: 20px; font-weight: 600; }
.poc { background: rgba(255,255,255,.2); padding: 2px 8px; border-radius: 6px; font-size: 12px; font-weight: 500; }
.status { font-size: 13px; opacity: .9; margin-left: auto; }
main { max-width: 720px; margin: 24px auto; padding: 0 16px; }
.setup {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
}
.setup h2 { margin-top: 0; font-size: 16px; }
.users { display: flex; gap: 12px; margin: 12px 0 16px; flex-wrap: wrap; }
.user-card {
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 12px 16px;
  cursor: pointer;
  background: white;
  min-width: 120px;
  transition: border-color .15s, background .15s;
}
.user-card:hover { border-color: var(--bf-blue-soft); }
.user-card.selected { border-color: var(--bf-blue); background: var(--mine); }
.user-card .uname { font-weight: 600; }
.user-card .ulang { font-size: 12px; color: var(--muted); }
label { display: block; font-size: 13px; color: var(--muted); margin: 12px 0 6px; }
input { width: 100%; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 16px; }
button {
  background: var(--bf-blue);
  color: white;
  border: 0;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  margin-top: 16px;
  font-weight: 500;
}
button:hover { background: var(--bf-blue-soft); }
.hint { font-size: 12px; color: var(--muted); margin-top: 16px; line-height: 1.5; }
.chat { background: var(--card); border: 1px solid var(--border); border-radius: 12px; overflow: hidden; display: flex; flex-direction: column; height: calc(100vh - 130px); max-height: 720px; }
.chat-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
  background: #fafbfd;
}
.chat-header .room, .chat-header .peers { color: var(--muted); }
.messages { flex: 1; overflow-y: auto; padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.msg { max-width: 80%; padding: 10px 14px; border-radius: 12px; font-size: 14px; line-height: 1.4; word-wrap: break-word; }
.msg.mine { align-self: flex-end; background: var(--mine); border: 1px solid #d4e0ff; }
.msg.theirs { align-self: flex-start; background: var(--theirs); border: 1px solid var(--border); }
.msg .from { font-size: 11px; color: var(--muted); margin-bottom: 2px; }
.msg .orig { color: var(--muted); font-size: 12px; font-style: italic; margin-top: 6px; }
.msg .translation { background: var(--translated); padding: 4px 6px; border-radius: 6px; margin-top: 4px; display: inline-block; }
.typing-indicator {
  padding: 4px 16px 8px;
  font-size: 12px;
  color: var(--muted);
  font-style: italic;
  min-height: 20px;
  opacity: 0;
  transition: opacity .2s;
}
.typing-indicator.active { opacity: 1; }
.composer { display: flex; gap: 8px; padding: 12px; border-top: 1px solid var(--border); }
.composer input { flex: 1; }
.composer button { margin-top: 0; }
.hidden { display: none; }

/* mobile */
@media (max-width: 600px) {
  main { margin: 12px auto; padding: 0 8px; }
  header { padding: 10px 14px; gap: 10px; }
  header h1 { font-size: 18px; }
  .status { font-size: 12px; }
  .chat { height: calc(100vh - 110px); max-height: none; }
  .msg { max-width: 88%; font-size: 13px; }
  .setup { padding: 16px; }
  .user-card { min-width: 100px; padding: 10px 12px; }
}